Glue modelling in variation management of compliant assemblies: critical issues and possible solutions

Variation management aims to reduce the effects of geometric variations of parts to assemble. Industry is facing a digital revolution in being able to manage geometrical deviation data along the entire lifecycle of a product. This requires the development of new assembly simulation models and tools. New design trends are orienting towards more and more lighter products. They are constituted by thin metal sheets or in composite material. Lighter products in composite materials are always joined through structural adhesive. This work presents different ways to model the adhesive inside a simulation that allows to predict the geometrical variations of an assembly constituted by compliant parts. Three different ways to model adhesive, i.e. glue contact, beam and shell elements, were taken into account. Different thickness values, different component constraints and application points of part variations were also considered. Two lighter assemblies were considered: one constituted by two metal plane sheets that are partially overlapped; the second is formed by three thin sheets in composite material, one plane and two L-shaped. The critical issues connected with the three different solutions to model adhesives in a simulation to manage geometric variations from component to assembly were underlined to guide a possible choice.